Laserfiche WebLink
<br />002478 <br /> <br />INTRODUCTION <br /> <br />The Sierra Cooperative Pilot Project (SCPP), a comprehensive research <br />program in cloud seeding for enhanced snowfall and runoff, began with <br />preliminary planning and discussions in 1972. <br /> <br />Several research projects along the crest of the Rocky Mountains <br />and in the Sierra Nevada have indicated that snowfall and resulting <br />streamflow can be increased by seeding specific types of weather <br />systems. Several commercial seeding projects in the Sierra report <br />consistent increases in streamflow of 5 to 8 percent. The physical <br />basis for the reported increases will be investigated to determine <br />whether greater increases can be obtained. <br /> <br />In 1973, the "Twelve Basin Investigation"l was completed by North <br />American Weather Consultants (NAWC), Goleta, California. This work <br />identified potential precipitation increases in 12 major river basins <br />of the Western United States by employment of a cloud seeding model <br />which developed precipitaion-temperature diagrams based upon 20 years <br />of historical precipitation and rawinsonde data. <br /> <br />Within the Sacramento River Basin, the Feather River study area water- <br />shed was judged to have the potential for 1 110 000 damJ (890,000 acre- <br />feet) of incremental runoff in an average year from the combined <br />microphysical and convective effects of weather modification. This <br />increase would be approximately 18 percent of the average annual runoff. <br /> <br />In the American River study watershed, the potential runoff from <br />cOlilbined microphysical and convective effects of weather modification <br />are about 370 000 dam3 (300,000 acre-feet). This increase in runoff <br />would result from an estimated 15.6 percent annual increase in snowfall <br />above 1220 metres (4000 feet) elevation. <br /> <br />The Twelve Basin Investigation conclusions clearly indicated addi- <br />tional feasibility research in weather modification technology was <br />merited within the Sacramento River Basin system as a means of pro- <br />viding future water supply alternatives. <br /> <br />In 1973, the State of California and the Bureau of Reclamation agreed <br />to pursue a research program in the Sierra Nevada, a program designed <br />to refine the technology and determine the feasibility of augmenting <br />runoff by cloud seeding. As a first step in the project, the State <br />and Bureau jointly funded a contract with the Center for Regional <br />Environmental Studies at San Diego State University for an assessment <br />of potential environmental effects that might require investigation. <br /> <br />In 1974, 21 public meetings were held in California and Nevada to <br />solicit comment on the proposed project and the draft report from <br /> <br />1. Elliott, Robert D., et a1., (1973). "Twelve Basin Investigation," <br />North American Weather Consultants, Goleta, California. <br /> <br />1 <br />